摘要:

AbstractT helper cell induction and the specificity of T cell‐mediated help as generated during alloreactive and H‐2‐restricted, virus‐ or hapten‐specific cytotoxic T lymphocyte (CTL) responses have been compared. With the use of a double‐chamber culture system, it was possible to dissect and separately analyze the induction phase of T helper cells from the T helper cell effector function. The data obtained revealed that during alloreactive as well as H‐2‐restricted T cell responses, antigen‐specific T helper cells are induced. Upon specific restimulation of T helper cells, helper cell function is mediated across a cell‐impermeable membrane via soluble products in an apparently nonspecific and nonrestricted manner. The data suggest that similar rules govern T‐T cell interactions in alloreactive and H‐2

ISSN:0014-2980    

DOI:10.1002/eji.1830100802

出版商:WILEY‐VCH Verlag GmbH    

年代:1980

数据来源: WILEY

摘要:

AbstractThy‐1+lymphocytes, detectable by quantitative serum absorption, arise in cultures of spleen cells from congenitally athymic (nu/nu) mice supplemented with supernatants from cultures of normal spleen cells stimulated with the T cell mitogen concanavalin A. Pretreatment of nu/nu spleen cells with appropriate anti‐Thy‐1 alloantibody and complement prior to culture reduces their capacity to generate Thy‐1+cells by about 90%. This shows that the majority of cells proliferating in these cultures are descendants of Thy‐1+cells which can be detected in the original nu/nu spleens. Experiments aimed at exploring the function of these Thy‐1+cells after culture in conditioned medium revealed that within one or two days after culture initiation, strong cooperative activity for a humoral response to xenogeneic erythrocytes can be detected. In mixtures of bone marrow‐derived lymphocytes from various mouse strains with cultured nu/nu spleen cells, it was observed that T‐B cooperation is not H‐2‐restricted. Attempts at inducing T cell‐mediated cytotoxicity to alloantigens in such cultures of nu/nu spleen cells were unsuccessful. In contrast, nonspecific cytotoxicity which was attributed to natural killer cells was regularly observed and could be maintained in these cultures

ISSN:0014-2980    

DOI:10.1002/eji.1830100803

出版商:WILEY‐VCH Verlag GmbH    

年代:1980

数据来源: WILEY

摘要:

AbstractThe specificity of mouse alloantibodies which blocked allogeneic killer cells has been confirmed as Ly‐2.2 using B 6 × C 3 H recombinant inbred (RI) strains. All of the RI strains tested were sensitive to the cell‐mediated lymphocytotoxicity (CML)‐blocking effect of our C3 H anti‐B 10.BR antisera and also carried the Lyt‐2ballele. This result and studies using Lyt‐2‐congenic strains firmly localized the genes encoding the target antigen of CML‐blocking antibodies in or near the Lyt‐2 locus. In addition, a monoclonal anti‐Lyt‐2.2 antibody was found to block the CML reaction of B 6 killer cells, but not that of B 6 Ly‐2.1 killers. Blocking antibodies to one allele blocked killing by Lyt‐2‐heterozygous F1killer cells, but the inhibition curve reached a plateau at a significantly lower level than that seen on the killer cells of the sensitive parent. Our results thus suggest that Lyt‐2 antigens are of functional significance on killer T cells, but do not reveal whether or not that significanc

ISSN:0014-2980    

DOI:10.1002/eji.1830100804

出版商:WILEY‐VCH Verlag GmbH    

年代:1980

数据来源: WILEY

摘要:

AbstractThis report describes the effect on various stages in the life cycle of the nematodesT. spiralisandN. brasiliensisof complement, antibodies from rats infected with these parasites and several different cell types. The cuticle of the infective larvae and adult worms of both nematode species activates complement via the alternative pathway, but the cuticle of newbornT. spiralislacks this property initially. As newborn larvae grow, however, the newly formed cuticle in the midregion of their body is able to activate complement. Rats infected with either nematode species produce antibodies to the cuticle of all life cycle stages which show marked specificity to each stage in the life cycle. Whereas the cuticle ofT. spiralisreacts evenly over the entire surface both to complement and to antibodies, the reaction of the cuticle ofN. brasiliensisto either reagent is patchy. Infective larvae ofN. brasiliensiswere killedin vitroin the presence of complement, by neutral red‐positive peritoneal macrophages which were nonadherent to plastic. The infective and newborn larvae ofT. spiraliswere killed by eosinophil‐enriched cell populations and antibodies. The speed of eosinophil killing of theT. spiralislarvae was enhanced when the serum was freshly collected and when the eosinophil suspension also contained neutral red‐positive nonadherent macrophages. Newborn larvae ofT. spiralisand infective larvae ofN. brasiliensisassumed a rigid appearance at death. Infective larvae ofT. spiralisburst, extruding their internal organs through their cuticle weakened by antibodies and the

ISSN:0014-2980    

DOI:10.1002/eji.1830100805

出版商:WILEY‐VCH Verlag GmbH    

年代:1980

数据来源: WILEY

摘要:

AbstractImmunological tolerance was induced in CBA mice with respect to both anti‐hapten and anti‐carrier IgE antibody production, following pretreatment of the animals with deaggregated ovalbumin. IgG antibody production was also affected. The tolerance was antigen‐specific, was stable upon adoptive transfer to irradiated syngeneic recipients, but was reversed following booster. The extent and duration of the tolerant state depended on the dosage and number of tolerogen injections. Tolerogen administered after the initiation of the primary response was without effect. The pattern and duration of this tolerance suggested that T suppressor cells were not involved. The adoptive transfer of spleen cells from tolerogen‐treated donors while being themselves unresponsive, failed to interfere with the induction of an immune response in the recipient. Evidence of T suppressor cell function was found in adoptive transfers, only after prolonged pretreatment of donors with a combination of tolerogenic and immunogenic forms of the carrier. These results suggested that T cell‐dependent tolerance of the IgE antibody response operates via two distinct mechanisms, of which only one is provided by suppressor cell

ISSN:0014-2980    

DOI:10.1002/eji.1830100806

出版商:WILEY‐VCH Verlag GmbH    

年代:1980

数据来源: WILEY

摘要:

AbstractA new monoclonal mouse antibody that recognizes a subset of rat peripheral T cells has been prepared by immunizing mice with rat thymocyte glycoprotein. This antibody, designated MRC OX 8, labels all peripheral T cells that are unlabeled by the previously described W3/25 monoclonal antibody. No peripheral T cells were found that bound both antibodies, but, in contrast, 90% of thymocytes were doubly labeled. Thoracic duct lymphocytes of congenitally athymic nude rats were not labeled by either antibody, but the spleens of such animals contained both W3/25+cells and MRC OX 8+cells. These splenocyte subpopulations did not overlap. Using the fluorescence‐activated cell sorter to isolate cells binding MRC OX 8 antibody, the phenotype of T cells mediating various T cell functions was established. Combining the present results with those published previously, it is shown that the cells providing help for antibody responses and those mediating graft‐vs.‐host reactions are phenotypically W3/25+MRC OX 8−. On the other hand, parental T cells that suppress antibody formation in F1hosts were identified as W3/25−MRC OX 8+. The relationship between the rat T cell subsets defined by these antibodies and those in the mouse identified by the Ly series of alloantibodies is discussed and a comparison made between the rat W3/25+subset and a recently identified human T ce

ISSN:0014-2980    

DOI:10.1002/eji.1830100807

出版商:WILEY‐VCH Verlag GmbH    

年代:1980

数据来源: WILEY

摘要:

AbstractThe gene products of the A and B regions of the rat major histocompatibility system (RT1) have been analyzed by immunoprecipitation and sodium dodecyl sulfate polyacrylamide gel electrophoresis. For antiserum production and as a source of target spleen cells, rat strains were used that differed only for various combinations of the RT1 regions. It could be shown that the RT1.A region, whose serologically detectable products behave like classical transplantation antigens, coded for molecules of 45 000 daltons that were associated with 12 500 dalton molecules. The RT1.B region products, which behave serologically like la antigens, consisted of two chains of 31 000 and 27 000 daltons, respectively. Thus, serological and biochemical phenotypes of the RT1 antigens could be matched in accordance with data obtained in other species and could be assigned to particular regions of the RT 1 system. The two‐peak structure of Ia antigens was only detectable under nonreducing conditions. After reduction, both peaks fused, presumably due to cleavage of intrachain disulfide bonds in the smaller chai

ISSN:0014-2980    

DOI:10.1002/eji.1830100808

出版商:WILEY‐VCH Verlag GmbH    

年代:1980

数据来源: WILEY

摘要:

AbstractThe quail‐chick marker system was used to investigate the mechanism of lymphoid precursor cells (LPC) homing to the early thymic rudiment during development of the avian embryo. Migration of LPC was demonstratedin vivoandin vitrofrom the yolk sac, spleen and bone marrow to the thymus rudiment at a definite period of the latter's ontogeny. Before and after this period, the thymic rudiment is nonreceptive for LPC. The onset of stem cell seeding depends on a stage‐dependent maturation of the thymic primordium while its arrest is regulated by the number of cells which have invaded the organ. Anin vitrotransfilter culture technique is described which permits LPC to be attracted to a thymic rudiment. The thymus at its physiological receptive period and several other organs were associated with LPC donors. The capacity of these various organs to induce LPC traffic was compared. It appeared that the “receptive” thymus is a much better “attractant” than the liver, the mesonephros or the already colonized thymic rudiment. The hypothesis of the production of a chemotactic factor responsible for LPC attraction by the thymus rudiment is proposed which accounts for experimental data reported in this article, as well as for the events of thymus ontogeny previously

ISSN:0014-2980    

DOI:10.1002/eji.1830100809

出版商:WILEY‐VCH Verlag GmbH    

年代:1980

数据来源: WILEY

摘要:

AbstractPeripheral blood leukocytes (PBL) from primed rabbits were able to suppress thein vitroanti‐sheep red blood cell (SRBC) plaque‐forming cell (PFC) response of autologous spleen cells. A population containing the suppressor cells could be isolated from PBL by cell fractionation on columns of insolubilized histamine. In contrast to spleen cells, PBL generated a weak secondary anti‐SRBC responsein vitro.A strong response was obtained with PBL freed from histamine‐binding (H+) cells. The addition of these H+cells to cultures of H−PBL caused strong suppression. The H+suppressor cell was further characterized as a radioresistant T cell. Low‐dose irradiation of H−cells resulted in a supplementary enhanced PFC response suggesting that PBL also contain a radiosensitive regulator cell which is not hist

ISSN:0014-2980    

DOI:10.1002/eji.1830100810

出版商:WILEY‐VCH Verlag GmbH    

年代:1980

数据来源: WILEY

摘要:

AbstractThis study presents a theoretical analysis of the phenotypic expression of the products of immune response (Ir) genes linked to the major histocompatibility complex. Recent evidence indicates that animals with “low”‐responder Ir genotypes can be induced to express adequate immune responses by minor variations in the manner or site of immunization. Hence, it is unlikely that Ir genes code for defective structural products in low‐responder animals. A quantitative model is presented of the behavior of Ir genes based on two principal elements: (a) clones of lymphocytes compete for prominence through processes of growth, differentiation and feedback suppression, and (b) Ir gene products influence the affinities of lymphocyte clones for antigenic determinants, without coding for the lymphocyte receptors for antigen. The theoretical analysis of this model leads to the conclusion that small differences in affinity on the level of single cells can be amplified through differential population growth and competition between clones of cells to produce a final response that appears “all‐or‐none” on a population level. Therefore, high or low responsiveness based on Ir genes can be explained by small shifts in the strength of interaction parameters. These small shifts can result from variation in H‐2 alleles, the mode of immunization, or the array of determinants on the immunogen; factors that were observed experimentally. These shifts in interaction parameters account for the observed flexibility of phenotypic expression of Ir genes. The model explains a number of immunological observations by a few basic facts or assumptions, and avoids the problem of postulating the existence of defects to account for low responsiveness. It aims at clarifying the relationship between systemic, macroscopic observations and the underlying cellular parameters. The translation of cellular characteristics into patterns of behavior manifested by populations of cells may not necessarily result in an averaging out of the characteristics, but could als

ISSN:0014-2980    

DOI:10.1002/eji.1830100811

出版商:WILEY‐VCH Verlag GmbH    

年代:1980

数据来源: WILEY